Is frozen water scattered in systems around other stars? Astronomers have long expected it is, partially based on previous detections of its gaseous form, water vapor, and its presence in our own solar system.<\/p>\n
Now there is definitive evidence: Researchers confirmed the presence of crystalline water ice in a dusty debris disk<\/a> that orbits a Sun-like star 155 light-years away using detailed data known as spectra<\/a> from NASA\u2019s James Webb Space Telescope. (The term water ice specifies its makeup, since many other frozen molecules are also observed in space, such as carbon dioxide ice, or \u201cdry ice.\u201d) In 2008, data from NASA\u2019s retired Spitzer Space Telescope hinted at the possibility of frozen water in this system.<\/p>\n \u201cWebb unambiguously detected not just water ice, but crystalline water ice, which is also found in locations like Saturn\u2019s rings and icy bodies in our solar system\u2019s Kuiper Belt<\/a>,\u201d said Chen Xie, the lead author of the new paper and an assistant research scientist at Johns Hopkins University in Baltimore, Maryland.<\/p>\n All the frozen water Webb detected is paired with fine dust particles throughout the disk \u2014 like itsy-bitsy \u201cdirty snowballs.\u201d The results published Wednesday in the journal Nature.<\/p>\n Astronomers have been waiting for this definitive data for decades. \u201cWhen I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but prior to Webb, we didn\u2019t have instruments sensitive enough to make these observations,\u201d said Christine Chen, a co-author and associate astronomer at the Space Telescope Science Institute in Baltimore. \u201cWhat\u2019s most striking is that this data looks similar to the telescope\u2019s other recent observations of Kuiper Belt objects in our own solar system.\u201d<\/p>\n Water ice is a vital ingredient in disks around young stars \u2014 it heavily influences the formation of giant planets and may also be delivered by small bodies like comets and asteroids to fully formed rocky planets. Now that researchers have detected water ice with Webb, they have opened the door for all researchers to study how these processes play out in new ways in many other planetary systems.<\/p>\n The star, cataloged HD 181327, is significantly younger than our Sun. It\u2019s estimated to be 23 million years old, compared to the Sun\u2019s more mature 4.6 billion years. The star is slightly more massive than the Sun, and it\u2019s hotter, which led to the formation of a slightly larger system around it.<\/p>\n Webb\u2019s observations confirm a significant gap between the star and its debris disk \u2014 a wide area that is free of dust. Farther out, its debris disk is similar to our solar system\u2019s Kuiper Belt, where dwarf planets, comets, and other bits of ice and rock are found (and sometimes collide with one another). Billions of years ago, our Kuiper Belt was likely similar to this star\u2019s debris disk.<\/p>\n \u201cHD 181327 is a very active system,\u201d Chen said. \u201cThere are regular, ongoing collisions in its debris disk. When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect.\u201d<\/p>\n Water ice isn\u2019t spread evenly throughout this system. The majority is found where it\u2019s coldest and farthest from the star. \u201cThe outer area of the debris disk consists of over 20% water ice,\u201d Xie said.<\/p>\n The closer in the researchers looked, the less water ice they found. Toward the middle of the debris disk, Webb detected about 8% water ice. Here, it\u2019s likely that frozen water particles are produced slightly faster than they are destroyed. In the area of the debris disk closest to the star, Webb detected almost none. It\u2019s likely that the star\u2019s ultraviolet light vaporizes the closest specks of water ice. It\u2019s also possible that rocks known as planetesimals<\/a> have \u201clocked up\u201d frozen water in their interiors, which Webb can\u2019t detect.<\/p>\n This team and many more researchers will continue to search for \u2014 and study \u2014 water ice in debris disks and actively forming planetary systems throughout our Milky Way galaxy. \u201cThe presence of water ice helps facilitate planet formation,\u201d Xie said. \u201cIcy materials may also ultimately be \u2018delivered\u2019 to terrestrial planets that may form over a couple hundred million years in systems like this.\u201d<\/p>\n The researchers observed HD 181327 with Webb\u2019s NIRSpec (Near-Infrared Spectrograph)<\/a>, which is super-sensitive to extremely faint dust particles that can only be detected from space.<\/p>\n The James Webb Space Telescope is the world\u2019s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).<\/p>\n To learn more about Webb, visit:<\/p>\n https:\/\/science.nasa.gov\/webb<\/a><\/p>\n Downloads<\/p>\n Click any image to open a larger version.<\/strong><\/p>\n View\/Download all image products at all resolutions<\/a><\/strong> for this article from the Space Telescope Science Institute.<\/p>\n Laura\u00a0Betz<\/strong>\u00a0–\u00a0laura.e.betz@nasa.gov<\/a> Claire Blome<\/strong> – cblome@stsci.edu<\/a> Christine Pulliam<\/strong> – cpulliam@stsci.edu<\/a> View Webb images<\/strong> of other debris disks around Vega<\/a>, Fomalhaut<\/a>, Beta Pictoris<\/a>, and AU Microscopii<\/a><\/p>\n Learn more<\/strong> about spectroscopy<\/a><\/p>\n Read more:<\/strong> Webb\u2019s Near-infrared Spectrograph<\/a> (NIRSpec)<\/p>\n More Webb News<\/a><\/strong><\/p>\n More Webb Images<\/a><\/strong><\/p>\n Webb Science Themes<\/strong><\/a><\/p>\n Webb Mission Page<\/a><\/strong> <\/p>\n What is the Webb Telescope?<\/strong><\/a><\/p>\n SpacePlace for Kids<\/strong><\/a><\/p>\n En Espa\u00f1ol<\/p>\n Ciencia de la NASA<\/strong><\/a><\/p>\n
NASA\u2019s Goddard Space Flight Center<\/a>, Greenbelt, Md.<\/p>\n
Space Telescope Science Institute<\/a>, Baltimore, Md.<\/p>\n
Space Telescope Science Institute<\/a>, Baltimore, Md.<\/p>\n